Electric heater



Oct. 2l, 1941.

F. w. PERRY 2,260,107

ELECTRIC HEATER med sept. 22, 193s 2 sheets-sheet 1 v" "hv I' V vIIl rwun. IIIl Il I Il'. f 1|" lill "hh 'In ATTQRNBS Oct. 21, 1941. F. w.PERRY ELECTRIC HEATER Filed Sept. 22 1938 2 Sheets-Sheet 2 a E M www@,f/ YT E mi y .N U W.l A ,n f u W n /v B Patented Oct. 21, 1941 ELECTRICHEATER.

Francis W. Perry, Dormont, Pa., assigncr'to Edwin L. Wiegand,Pittsburgh, Pa.

Application September 22, 1938, Serial No. 231,185

20 Claims.

My invention relates to electric heaters in general, and moreparticularly to supporting means for one or more electrical heatingelements. Electric heaters embodying my invention are particularlyyadapted for use in electric ranges. The principal object of my inventionis to provide new and improved electric heaters of these types.

In the drawings accompanying this specification, and forming a part ofthis application, I have shown, for purposes of illustration severalforms which my invention may assume, and in these drawings:

Figure 1 is a side elevation of an electric range unit embodying myinvention,

Figure 2 is a bottom View of the range unit shown in Figure l, but withthe reflector and the means for connecting it to the range unit omitted,and a part shown fragmentarily,

Figure 3 is a fragmentarysectional view, on an enlarged scale, taken onthe line 3 3 of Figure 2, looking in the direction of the arrows, butwith the reilector and connecting means included,

Figure 4 is a fragmentary perspective View of disassembled details,

Figure 5 is a bottom View, similar Vto Figure 2, but of anotherembodiment of my invention,

Figures 6, 7, and 8 are fragmentary sectional views taken on the lines 66, 1 1, and 8-8 respectively, of Figure 5, looking in the direction ofthe arrows, x

yFigure 9 is a View similar to VFigure 2, but of another embodiment ofmy invention, andr Figure 10 is a fragmentary sectional view taken alongthe line 10-10 of Figure 9, looking in the direction of the arrows.

Referring to Figures 1 through 4, the range unit 20 here shown comprisesone or more electrical heating elements (here shown as two in number)2|, 22. The heating elements 2l, 22 are in this instance of ring form,constructed and arranged so that they are concentric. The heatingelements 2l, 22 are here shown as supported from a stove top 23 by asupporting means which, 'in this instance, includes a support ring 24resting cn the stove top 23 having an aperture 26, and includes asupport 21 which is here shown as supported by the support ring 24. Thesupport 21 serves as a support for the heating elements 2| 22 as willhereinafter more fully appear. The range unit 20 also includes a reector28 disposed beneath and supported by the support 21.

The support 21, as here shown, is of cast metal and comprises threeprincipal generally radial 55 pacted'to a'dense hard'condition.

arms .29, 30, 3|, and two auxiliary arms 32, 33, integrally joined attheir outer ends to a generally heart-shaped frame 34, and integrallyjoined at their innerr ends to an arcuate portion 35. Each of theprincipal arms, 29, 30, 3|, is here shown as comprising a pair ofgenerally radially spaced bushings 36, 31 of inverted cup-like form.Each bushing has an aperture 38 in the top thereof, theseapertures beingdesirably slightly elongated in a generally radial direction, as may bebest seen in Figure 4. Disposed in each pair of bushings 35, 31 is alever or saddle 39, one of which may be seen in perspective in Figure 4,disassembled from the bushings 3B, 31 there shown. )inasmuch as thesaddles 39 are all identical and each cooperates with its pair ofbushings 36, 31 in the same Way, a description of one will serve forall.

The saddle 39 comprises a flat central portion 40 adapted to be insertedin a slot 4I in the portion A42 joining the bushings 36, 31. Theentrance portion of the slot 4I joins the two apertures 38 in thebushings 36, 31. The slot 4| is bridged transversely, below its entranceportion, by a V-shaped bridge or knife edge fulcrum 43, this fulcrurnand the similar fulcrums (not visible) associated with the other sets ofbushings 36, 31 in the arms 29, 3|, being in this instance, eachdirectly below a space 44 left between the heating elements 2l, 22. Thecentral portion 40 of the saddle is provided with a V-shaped notch 45,of larger angle than the V-shaped fulcrum 43, as may be best seen inFigure 3. At the ends of the central portion 40 of the saddle there areprovided tubular portions 46a, 4Gb, here shown as of elliptical orgenerally elongated cross-section. The lower ends 41 of the tubularportions 46a, 4Gb are here shown as generally plane, whereas the upperends are here shown as V-shaped, each upper end providing two fulcrums48.

The heating elements 2l, 22, are here shown as constructed and arrangedin the following manner, to cooperate with the saddles 39. The heatingelements 2|, 22 may be of any desired form; they are here shown as eachcomprising a metallic sheath 49 within which is disposed any desiredform of resistor 50, here shown as of the strip type. The resistor 50may be embedded in refractory electrical-insulating heatconductingmaterial 5l, and this material may be in the form of suitable granular,comminuted or powdered refractory material, preferably com- The heatinga head 58 within the sheath 49 of the respective heating element, theShanks of the rivets projecting downwardly, as viewed in Figure 3,v

through openings in bottomportions 59 of the respective sheaths. vdisposed in recesses formed by bosses 69, and

these bosses may be strengthened by ridges '6|,.

embossed to a less degree than the bosses. Parts of the ridges 6| arevisible in Figure Y2. shanks of the rivets extend downwardly through thetubular, portions 46a, 46h of the saddlesl 39. The heating elements 2|,22 may be held assembled with the saddles 39 in any desired manner. Tothis end, the ends of the shanks of the rivets are here shown asbifurcated longitudinally, the ends 62 of the furcations being spreadapart, and, in this instance, two Washers 63, 64 are disposed, on eachshank, between the surface 41. of the lower end of the respectivetubular portion and the bent furcations 62 of the respective rivetshank. Desirably,v a washer, 65 may be interposed between :each boss 60,and the fulcrums 48 provided at vthe upper ends of the tubular portions46a, 4612, so that when the heating elements 2|, 22 are assembled withthe saddles 39, a boss 69 normally rests on a washer 65, and the washerrests on the fulcrums 48, as may be seen in Figure 3. The washers' 65may be of less diameter than the minor axis of therespective apertures38. Downward movement of either one of the heating elements 2|, 22, isstopped, after predetermined movement from the position shown in Figure3, by engagement of an under surface of the heatingelement with atopsurface of `a re*- spective one of the bosses 36, 31, in this instanceby engagement of the ridges 6| with lugs 66 which may be provided oneach of the bosses 36, 31.`

In vorder to permit the freedom of movement necessary for the desiredoperation of the parts, the construction and arrangementissuch that adesired space is left between the uppermost Washer, 64, and the surface41 of the lower end of the saddles assembled therewith, while they maybe lifted upwardly a predetermined amount, cannot be removed from thesupport 21 by such movement, since the washers 64 will abut the undersides of the tops of the bosses 36, 31.

The range unit 20 is desirably provided with the reector 28 and this ishere shown as'having a vprincipal portion `61 of generally conical form,the upper surface extending downwardly from the centerV of thereflector.V The central portion of theY refiector has a slightlydownwardly dished portion 68 provided withanfaperture 69. In the portion61, near the junction betweenthe portions 61, 68, are at least twocircumferentially Sptccd'apertures (one of which, 16, maybe seen The' inFigure 3) into which extend rounded projections 1| formed integrally onthe support 21. These projections, 1| are here shown as provided on thearms 36, 3| of the support 21. The projections 1|, in cooperation withthe apertures 10, serve to locate the reflector 26 and hold it fromcircumferential movement, and the reflector is here shown as held inposition against the The rivet heads- 58 may be y19 cooperating with thewing nut 13.

support 21, by means of a bolt 1.2 and wing nut 13. The bolt is hereshown as comprising a sheet metal head including a cup 14, the top ofwhich is below the level of the upper surfaces of the heating elements2|, 22, and including also a cup 15 nested in the cup 14. Flanges 16, 11of the cups 14, 15 are here shown as tapering downwardly and inwardlyslightly so that the cups are firmly held together. The cup 15 has itscentral portion 18 dished downwardly and is here shown Vaperture 69which is almost as large as the wing nut, the aperture 69 providing afree opening at the center of the reflector.

The resistor 50 within the element 22 is suitably connected to a pair ofterminal studs 83, 84, and the resistor 50 of the element 2| is suitablyconnected to a vpair of terminal studs 85, 86, all of these studs beingdesirably so located that they are disposed circumferentially between.the arms 3U, 3| when the elements are assembled with the support 21. Asuitable insulating conductorl terminal connection block 81 may beprovided, the block having separate chambers in which are disposedconductors 88, 89, 90. The conductor 88 is connected to the terminalstud 85; the conductor 89 is vconnected to the terminal stud 83; and theconductor'90 is connected to the terminal stud 84.v The terminal stud 83of the heating element 22 is connected to the terminal stud 86 of theheating element 2|, by means of a conductor 9|. In view of the fact thatthe heating elements 2|, 22 are movable'with respect to some fixedpoint, the conductors 88, 9| are desirably made exible, and one way inwhich this may be done is to make these conductors of laminated form,the laminations being of desired thinness and number to secure the`desired flexibility and conducting capacity. In Figure 2 one of theconductors, 9|, is broken away to show its laminated construction. Thesupport ring 24 is here shown as comprising an Yannular generallyhorizontalportion 92, and at its outer` periphery has a downwardlyextending cylindrical flange 93, the lower margin of which is adapted torest on the stove top 23. The inner periphery of the annular portion 92has a downwardly extending generally cylindrical longer nange 94. Thejunction portions between thev annular portion 92 and the flanges' 93,94 respectively are desirably rounded. The flange 94 is provided withthree apertures 95', on the lower margins of which shoulders 96,provided on the frame 34, areadapted to rest, the construction andarrangement being such that when the support 21 and support ring 24 areassembled, ,the

upper surfaces of the heating elements 2|, 22 are desirably somewhatabove the top of the annular portion 92 of the support ring 24.

The usual practice in electric ranges is to have the uppermost surfacesof the heating element or elements define a fixed single plane. Suchconstruction of course will give maximum propinquity between the heatingsurfaces and the surface of the part to be heated, provided the surfaceof the part to be heated is also a plane. Cooking vessels, however,irrespective of their original form, ordinarily do not satisfy thatcondition, some having the bottom thereof bulged outwardly'and somebulged inwardly. In fact, some cooking vessels are originally made withthe bottom slightly recessed in the central region. While theseVariations from a plane form are not great, it has been found that arelatively small air space between the bottom of a Vessel and thesurface of the heating element or elements materially slows down theheating speed, raises the temperature of the heating element and lowersthe running efliciency of the element and also tends to shorten the lifeof the element.

It will be evident that if the heating elements are movably mounted, ashereinbefore described, that the upper surfaces of the heating elementswill be adjusted to and adapt themselves to the surfaces of varioustypes and forms of vessels placed thereon. For example, in case a vesselwhich has the central portion of the bottom thereof slightly recessedupwardly, is placed upon a. range unit such as herein disclosed, theportion of the bottom of the vessel which surrounds the central recessedportion of the bottom will push downwardly on the upper surface of theele-ment 2|, thereby causing the saddles 39 to swing about their pivotsand push the element 22 upwardly into contact with the central recessedportion of the bottom of the vessel. On the other hand, if the centralportion of the vessel is bulged downwardly somewhat, the element 22 willbe pushed downwardly, thereby causing the saddles 39 to swing and pushthe element 2| upwardly into contact with the outer part of the bottomof the vessel. It will be evident that the described construction andarrangement permits such swinging of the saddles 39 with respect to theheating elements. The downward movement of a heating element, from itsposition shown in Figure 3, is limited as hereinbefore described. Themaximum relative movement of the heating elements 2|, 22 is of coursedouble the movement of one element in the illustrated embodiment. The

aforesaid relative movement need be only slight to take care ofsubstantially usual conditions.

From the foregoing it will be apparent that the saddles 39 serve toequalize the forces acting against the upper surfaces of the heatingelements 2|, 22. Accordingly, it will be further' apparent thatequalization will take place even though the forces acting on either ofthe elements are not uniformly circumferentially distributed. Forexample, the forces may be such as to move the element 2| downwardly atone place and to move it upwardly at another place, the unit 22 beingcorrespondingly moved in respectively opposite directions at thoseplaces. This would occur vif the bottom of the vessel is not bulgedoutwardly, or inwardly, uniformly.

Referring to the embodiment shown in Figures through 8, a support 21asimilar to the support 21 of the embodiment of Figure 2 is provided forsupporting heating elements 2|a., 22a. However, in this instance, noslots and fulcrums, such as the slots 4| and fulcrums 43 of theembodiment of Figures 1 through 4 are provided in the arms 29a, 30a, 3|aof the support 21a. The heating elements 2|a, 22a are identical with theheating elements 2|, 22 but the rivets 52a to 51a inclusive, are shorterthan the rivets 52 to 51 inclusive, and the washers 91, provided on therivets 52a to 51a, are spaced from and adapted (after predeterminedmovement) to engage the under side of the tops of the bushings 36a, 31arespectively.

As here shown, two levers or saddles 98, 99 are suitably pivoted,intermediate their ends, on machine screws |00, screwed into portions|0|, |02, of the support 21a, which extend in a generally radialdirection. Bottom surfaces of the heating elements 2id, 22a respectivelyrest on opposite end portions of the saddles 98, 99, as shown in Figure1; and these saddles are so constructed and arranged that when a saddleis in the position shown in Figure '7, the tops of the heating elementsare flush, and, consequently, as is apparent from Figure 6, eitherelement 2id, 22a, may move downwardly a predetermined amount, ashereinbefore explained, thereby swinging the saddle and causing theother element to move upwardly at that saddle.

As here shown, two additional levers or saddles |03, |04 are provided,each having a V-shaped seat |05 intermediate its ends, as shown inFigure 8, these seats being adapted to rest on V- shaped fulcrums |06,|01 respectively, provided at the bottoms of notches |09 in the portionsof the frame 34a between the arm 29a and the auxiliary arms 32a, 33arespectively. Each end of each of the saddles |93, |04 is here shown asprovided with a generally cylindrical transversely extending portion l0.As may be seen from Figure 8, bottom surfaces of the heating elements 2id, 22a respectively rest on the end portions I0, the saddles |03, |04being constructed and arranged to function as already stated inconnection with the saddles 98, 99.

Referring now to the embodiment shown in Figures 9 and 10, a support21h, similar to the support 21a of the embodiment of Figure 5, isprovided for supporting heating elements 2lb, 22h. These heatingelements are associated with the support 211) in the same manner as arethe heating elements 2|a, 22a with the support 21a, that is, as shown inFigures 5 and 6. However, the support 21h differs from the support 21ashown in Figure 5 in that pivot rods ||2 are provided between thejunctions of the bosses 36h, 31h of the arms 3019, 3|b respectively, andthe arcuate portion l |3. Two other pivot rods ||4, ||5 are also hereshown as provided between opposite sides respectively of the junction ofthe bosses 36h, 31h of the arm 29h and portions of the frame 34h betweenthe arm 29h and the auxiliary arms 32D, 33h respectively. On each ofthese pivot rods, ||2, ||4, I|5, is swingably seated a saddle ||6, suchas shown in Figure 10. Each saddle ||6 has a recess ||1 with a roundedseat complementary to any of the pivot rods, and has a pair of upwardlyextending fulcrum projections ||8 on which bottom surfaces cf theheating elements 2 |17, 22D respectively rest. Collars ||9 may beprovided on the pivot rods to hold the saddles ||9 against longitudinalmovement on the rods.

It will be evident that the embodiments respectively shown in Figures 5through 8, and in Figures 9 and 10, will serve to adjust the surfaces ofthe heating elements to the surface of vessels placed thereon in amanner analogous to that already described in connection lwith theembodiment of Figures 1 through 4.

From the foregoing it will be apparent to those skilled in the art thateach of the illustrated embodiments of my invention provides a new andimproved electric heater, and accordingly, each accomplishes theprincipal object of my invention. On the other hand, it also will beobvious to those skilled in the art that the illustrated embodiments ofmy invention may be variously changed and modied, or features thereof,singly or collectively, embodied in other combinations than thoseillustrated, Without departing from the spirit of my invention, orsacricing all of the advantages thereof, and that accordingly, thedisclosure herein is illustrative only, and my invention is not limitedthereto.

I claim:

1. Electric heating apparatus, comprising: a plurality of electricalheating elements; means mounting said heating elements for relativemovement; and means s o constructed and arranged that a force causingmovement of one of said heating elements will positively cause movementof another of said elements.

2. Electric heating apparatus, comprising: a plurality of electricalheating elements; means mounting said heating elements for relativemovement; and means so constructed and arranged that a force causingmovement in a given direction of a part of one of said heating elementswill cause movement in an opposite direction of an adjacent part ofanother of said elements.

3. Electric heating apparatus, comprising: at least two electricalheating elements; means constructed and arranged to movably mount saidheating elements; and means, including a lever having a pivotintermediate its ends, so constructed and arranged that said heatingelements are adapted respectively to engage said lever at opposite sidesof said pivot.

4. Electric heating apparatus, comprising: at least two electricalheating elements; and means constructed and arranged to mount saidheating elements with adjacent marginal portions thereof spaced topermit relative movement; and means, including a lever having a pivotintermediate its ends, said pivot being disposed approximately oppositethe space between said elements, so constructed and arrangedA that saidheating elements are adapted respectively to engage said lever atopposite sides of said pivot.

5. Electric heating apparatus, comprising: a plurality of Aheatingelements having surfaces adapted for cooperation with a surface of adevice to be heated, each of said heating elements being of annular formconcentrically disposed; means mounting said heating elements forrelative movement in the general direction of the common axis of saidelements; and means so constructed and arranged that relative pressurebetween said heating elements and the device to be heated causesadjustment of said heating element surfaces with respect to the surfaceof the device to be heated.

6. Electric heating apparatus, comprising: a plurality of heatingelements having surfaces adapted for cooperation with a surface of adevice to be heated, each of said heating elements being of annular formand concentrically disposed; means mounting each of said heatingelements for universal movement with respect to their common axis; andmeans so constructed and arranged that relativepressure between saidheating elements and the device to be heated causes adjustment of saidheating element surfaces with respect to the surface of the device to beheated.

'7. Electric heating apparatus, comprising: a plurality of heatingelements having surfaces adapted for cooperation with a surface of adevice to be heated; means mounting said heating elements for relativemovement; and means, including a plurality of levers pivotedintermediate their ends and engageable at opposite sides of their pivotsby certain of said heating elements, so constructed and arranged thatrelative pressure between said heating elements and the device to beheated actuates one or more of said levers to cause adjustment of saidheating element surfaces with respect to the surface of the device to beheated.

8. Electric heating apparatus, comprising: a plurality of heatingelements having surfaces adapted for cooperation With a surface of adevice to be heated, each of said heating elements being of annular formconcentrically disposed;

Y means mounting said heating elements for relative movement in thegeneral direction of the common axis of said elements; and means,including a plurality of levers pivoted intermediate their ends andengageable at opposite sides of their pivots by certain of said heatingelements, so constructed and arranged that relative pressure betweensaid heating elements and the device to be heated actuates one or moreof said levers to cause adjustment of said heating element surfaces withrespect to the surface of the device to be heated.

9. Electric heating apparatus, comprising: a plurality of heatingelements having surfaces adapted for cooperation with a surface of adevice to be heated, each of said heating elements being of annular formconcentrically disposed; means mounting said heating elements foruniversal movement with respect to their common axis; and means,including a plurality of levers pivoted intermediate their ends andengageable at opposite sides of their pivots by certain of said heatingelements, so constructed and arranged that relative pressure betweensaid heating elements and the device to be heated actuates one or moreof sai-d levers to cause adjustment of said heating element surfaceswith respect to the surface of the device to be heated.

10. An electric range unit, comprising: an electrical heating element;supporting means for said element, said supporting means having anaperture; and means, Vincluding at least one stud carried by saidelement and extending through said aperture, so constructed and arrangedas to mechanically hold said heating element 'connected to saidsupporting means and permit limited relative movement of said heatingelement to- Ward and away from said supporting means.

11. An electric range unit, comprising: a support; a heating elementhaving a surface adapted for cooperation with a surface of a device tobe heated, said element being movable With respect to said support;control means, including a part movably mounted on saidV support andserving to support said element, so constructed and arranged thatrelative pressure between said heating element and the device to beheated causes adjustment of said heating element surface with respect tothe surface of the device to be heated; and positive stop means,including a part carried by said element and engageable with saidcontrol means, so constructed and arranged as to limit movement of saidelement away from said support.

12, An electric range unit, comprising: a support; a heating elementhaving a surface adapted for cooperation with a surface of a device tobe heated, said element being movable with respect to said support;control means, including a lever pivoted on said support, so constructedand arranged that relative pressure between said heating element and thedevice to be heated causes adjustment of said heating element surfacewith respect to the surface of the device to be heated; and positivestop means, including a part carried by said element and engageable withsaid lever, so constructed and arranged as to limit movement of saidelement away from said support.

13. An electric range unit, comprising: a grid; a plurality ofelectrical heating elements disposed over said grid, said heatingelements being relatively movable in a direction toward or away fromsaid grid; and means so constructed and arranged that a force causingmovement of one of said heating elements will thereby positively causemovement of another of said elements.

14. An electric range unit, comprising: a grid; a plurality ofelectrical heating elements disposed over said grid, said heatingelements being relatively movable in a direction toward or away fromsaid grid; and means so constructed and arranged that a force causingmovement in a given direction of a part of one of said heating elementswill thereby cause movement in an opposite direction of an adjacent partof another of said elements.

15. Electric heating apparatus, comprising: a plurality of electricalheating elements having surfaces for cooperation with a surface of adevice to be heated; supporting means for said elements, said supportingmeans having apertures; means, including studs carried by said elementsand extending through said apertures, so constructed and arranged as tomechanically hold said heating elements connected to said supportingmeans and permit limited relative movement of said heating elementstoward and away from said supporting means; and means so constructed andarranged that relative pressure between said heating elements and thedevice to be heated causes adjustment of said heating element surfaceswith respect to the surface of the device to be heated.

16. Electric heating apparatus, comprising: a plurality of electricalheating elements having surfaces for cooperation with a surface of adevice to be heated; supporting means for said elements, said supportingmeans having apertures, means, including studs carried by said elementsand extending through said apertures, so constructed and arranged as tomechanically hold said heating elements connected to said supportingmeans and permit limited relative movement of said heating elementstoward and away from said supporting means; and means so `constructedand arranged that a force causing movement of one of said heatingelements will thereby cause movement of another of said heatingelements.

17. An electric range unit, comprising: a support having an aperture; alever pivoted on said support, said lever having an aperture; a heatingelement having a surface adapted for cooperation with the surface of adevice to be heated, said element being movably mounted with respect tosaid support and being engageable with said lever; and lost motionconnection means between said element and said lever, said connectionmeans including a stud carried by said element and extending throughsaid apertures, and said connection means being so constructed andarranged that disengagement of said stud from said lever is prevented.

18. Electric heating apparatus, comprising: a plurality of relativelymovable heating elements having surfaces adapted for cooperation with asurface of a device to be heated; supporting means for said elements,including a plurality of levers pivoted intermediate their ends andengageable at opposite sides of their pivots by certain of said heatingelements, so constructed and arranged that relative pressure betweensaid heating elements and the device to be heated actuates one or moreof said levers to cause adjustment of said heating element surfaces withrespect to the surface of the device to be heated.

19. Electric heating apparatus, comprising: a plurality of relativelymovable heating elements having surfaces adapted for cooperation with asurface of a device to be heated; supporting means for said elements,including means, engageable by said elements, for transmitting pressurefrom one element to another; and said pressure transmitting means beingso constructed and arranged that relative pressure between one of saidheating elements and the device to be heated causes pressure to betransmitted through said pressure transmitting means to cause adjustingmovement of another of said elements with respect to the device to beheated.

20,Electric heating apparatus, comprising: a support; a plurality ofrelatively movable heating elements having surfaces adapted forcooperation with a device to be heated; a plurality of levers pivotedintermediate their ends on said support, said levers having apertures;said heating elements and said levers being relatively so constructedand arranged that certain of said levers are engageable at oppositesides of their pivots by certain of said heating elements; and lostmotion connection means between said certain elements and levers, saidconnection means including studs carried by said elements andcooperating with respective ones of said apertures, and said connectionmeans being so constructed and arranged that disengagement of said studsfrom the respective said levers is prevented.

FRANCIS W. PERRY.

